Percutaneous Thermal Ablation for Managing Small Renal Metastatic Tumors.

Purpose: To retrospectively evaluate the treatment outcomes of thermal ablation for renal metastatic tumors. Materials and Methods: Thirteen consecutive patients with small renal metastatic tumors (≤3 cm), who underwent thermal ablation between 2009 and 2020, were included in this study. Eight patients had extra-renal tumors during renal ablation. The primary tumors were adenoid cystic carcinoma in four patients, lung cancer in three, hemangiopericytoma in three, leiomyosarcoma in two, and thyroid cancer in one. The therapeutic effects, safety, survival rate, prognostic factor, and renal function were evaluated. Results: We performed 18 ablation sessions (cryoablation, n = 13; radiofrequency ablation, n = 5) on 19 renal metastases with a mean diameter of 1.7 cm, which resulted in a primary technique efficacy rate of 100% without procedure-related deaths or major complications. Renal function significantly declined 6 months after ablation (P = 0.0039). During the mean follow-up period of 31.2 ± 22.4 months (range, 2.7-71.4 months), one patient had local tumor progression at 11.9 months following radiofrequency ablation. The overall survival rates at 1 and 3 years after ablation were 76.9% (95% confidence interval [CI], 54.0%-99.8%) and 59.3% (95% CI, 31.3%-87.3%), respectively. Tumor size ≥ 2 cm (P = 0.02) and metastasis from non-small cell lung cancer (P = 0.001) were significant worse prognostic factors in univariate analysis, and metastasis from non-small cell lung cancer (P = 0.01) was significant in multivariate analysis. Conclusions: Percutaneous thermal ablation for small renal metastases is safe and feasible and can control local tumors.

Use of Microballoon Catheter in Transarterial Ethanol Embolization of Renal Angiomyolipoma: A Retrospective Comparative Study with Historical Control?

Purpose: To clarify the utility of microballoon catheter in renal arterial ethanol embolization of renal angiomyolipoma (AML). Material and Methods: A total of 20 patients (15 women, 5 men) with median age of 45 years (39-60 years) underwent embolization to treat 22 AMLs. A mixture of ethanol and iodized oil was injected into the feeding arteries of 13 tumors using balloon occlusion (the balloon embolization group) with a microballoon catheter and 9 tumors without using balloon occlusion (the non-balloon embolization group). Changes in the maximum tumor diameter, tumor volume, and adverse events were evaluated. Result: The median baseline maximum tumor diameters and volumes were 6.3 cm and 61.4 cm3 in the balloon embolization group, and 4.6 cm and 40.1 cm3 in the non-balloon embolization group, respectively. Tumor enhancement disappeared on postembolization angiography in all cases. All tumors shrunk after embolization. There were no statistically significant differences in the percent decrease in the maximum tumor diameter and volume at 10-12 month between balloon occlusion group (31.5% and 67.9%) and control group (34.8% and 62.6%). Fever was significantly more frequent when balloon occlusion was used: 38% vs. 0% (p = 0.03). No major complication was observed in either patient group. Conclusions: Balloon occlusion may not affect tumor shrinkage when embolizing AMLs with a mixture of ethanol and lipiodol.

Computed tomography-guided biopsy for small renal masses before or immediately after tumor ablation: factors affecting diagnostic yield.

PURPOSE: To evaluate the diagnostic yield of percutaneous renal mass biopsy (RMB) before and after ablation. MATERIALS AND METHODS: In total, 333 renal masses in 332 consecutive patients underwent computed tomography (CT)-guided biopsies and were included in this study. All biopsies were performed with 18-gauge core needles with CT fluoroscopic guidance before ablation (n = 234) or immediately after radiofrequency ablation (RFA) (n = 40) or cryoablation (CA) (n = 59). The safety and diagnostic yield of RMB were evaluated. Both univariate and multivariate analyses were used to identify factors affecting diagnostic yield. RESULTS: No major complication occurred. The 281 specimens (84%) were diagnostic. There were 257 renal cell carcinomas (77%), 21 benign masses (6%), and 3 metastases (1%). The remaining 52 specimens (16%) were nondiagnostic. The diagnostic yields before ablation, after RFA, and CA were 91% (212/234), 80% (32/40), and 63% (37/59), respectively. Small masses (P = 0.050 and 0.006), cystic masses (P < 0.001 and < 0.001), and post-CA (P < 0.001 and < 0.001) were independent and significant factors affecting the nondiagnostic results in both univariate and multivariate analyses. CONCLUSION: CT-guided RMB can be nondiagnostic when the tumor is small, cystic, or biopsied immediately after CA.

Percutaneous Image-guided Thermal Ablation for Renal Cell Carcinoma.

Nephrectomy is the gold standard for the treatment of renal cell carcinoma (RCC). However, some patients are not suitable candidates for nephrectomy because of high surgical risk, reduced renal function, or the presence of multiple renal tumors. Percutaneous image-guided thermal ablation, including cryoablation and radiofrequency ablation, is a minimally invasive and highly effective treatment and can be used to treat RCC in patients who are not good candidates for surgery. This article will review percutaneous image-guided thermal ablation for RCC, covering treatment indications, ablation modalities and techniques, oncologic outcomes, and possible complications. In addition, the characteristics of each ablation modality and its comparison with nephrectomy are also presented.

Is FDG-PET/CT Useful for Diagnosing Pulmonary Metastasis in Patients with Soft Tissue Sarcoma?

BACKGROUND/AIM: In patients with soft tissue sarcoma (STS), distinguishing small metastatic pulmonary nodules from benign ones remains difficult. This study aimed to determine the accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in detecting pulmonary metastasis and identify factors affecting sensitivity with STS. MATERIALS AND METHODS: The clinical records and chest CT and FDG-PET/CT scans of 102 patients with STS were reviewed to determine the presence of pulmonary nodules. RESULTS: A significant relationship was observed between nodule size and maximum standardized uptake value (SUVmax). For nodules smaller than 5 mm, only 10 out of 76 metastatic pulmonary nodules exhibited FDG accumulation, showing a weak correlation between nodule size and SUVmax Conclusion: The role of FDG-PET/CT in differentiating metastatic from benign pulmonary nodules was unsatisfactory, especially for small nodules. Careful follow-up using CT scan may still be appropriate for diagnosing pulmonary nodules smaller than 5 mm.

Role of curative treatment in patients with intermediate-stage hepatocellular carcinoma.

PURPOSE: To retrospectively evaluate the role of curative treatment in patients with intermediate-stage hepatocellular carcinomas (HCCs), and to identify the subgroup having benefit from curative treatment. METHODS: From April 2000 to December 2014, 100 patients with intermediate-stage HCCs underwent either curative treatment (hepatectomy: n = 23, radiofrequency ablation (RFA); n = 29, both: n = 4) or transarterial chemoembolization (TACE): n = 44) as initial treatments for HCCs. Overall survival, influence of treatment allocation on prognosis, and factors affecting treatment allocation were evaluated. RESULTS: The 5-year survival rate was 59.2% [95% confidence interval (CI) 51.6-66.8%] in the curative group, and 25.1% (95% CI 11.5-38.7%) in the TACE group. Treatment allocation was the only significant prognostic factor (p = 0.014, hazard ratio: 0.382, 95% CI 0.177-0.821). The curative group consisted of more patients with Child-Pugh A (p = 0.0016) than the TACE group, a tumor number of 3 or fewer (p < 0.0001), a unilobar tumor location (p = 0.02), within 4 of 7 cm criterion (p = 0.001), and within up-to-7 criterion (p = 0.04). Child-Pugh A, within the 4 of 7 cm criterion, and a unilobar tumor location were significantly linked with treatment allocation in multivariate analysis. CONCLUSIONS: Curative treatment can prolong survival in selected patients with intermediate-stage HCCs.

Clinical utility of radiofrequency ablation following transarterial injection of miriplatin-iodized oil suspension in small hepatocellular carcinoma.

PURPOSE: To retrospectively evaluate the clinical utility of radiofrequency ablation (RFA) following transarterial injection of miriplatin-iodized oil suspension (MPT-RFA) for hepatocellular carcinoma treatment. MATERIALS AND METHODS: We evaluated clinical outcomes of MPT-RFA for three or fewer hepatocellular carcinomas. Twenty-one patients with 30 tumors (maximum diameter: mean 1.4 ± 0.4 cm, range 0.7-2.2 cm) received MPT-RFA. RESULTS: Nineteen patients (90.5 %, 19/21) achieved complete ablation at the first RFA session. Two patients (9.5 %, 2/21) required a second RFA session but achieved complete ablation. Primary and secondary technical success rates were 90.5 and 100 %. There were no deaths related to the procedures performed. Grade 3 or 4 increases in the serum aspartate aminotransferase, alanine aminotransferase, and bilirubin levels were found in six patients (38.1 %, 8/21). There were no liver infarctions. During the median follow-up period of 24.1 months (mean ± SD 24.7 ± 6.9 months, range 13.8-38.9 months), the local tumor progression rate and overall survival rate at 2 years was 5.0 % (95 % confidence interval 0.3-20.6 %) and 86.7 % (95 % confidence interval 56.3-96.5 %), respectively. The mean hospital stay was 8.4 ± 3.1 days (range 5-18 days). CONCLUSION: MPT-RFA is a safe therapeutic option that initially provides therapeutic results.

Long-Term Results of Stent Placement in Patients with Outflow Block After Living-Donor-Liver Transplantation.

PURPOSE: To evaluate long-term results of stent placement retrospectively in patients with outflow block after living-donor-liver transplantation (LDLT). MATERIALS AND METHODS: For this institutional review board approved retrospective study conducted during 2002-2012, stents were placed in outflow veins in 15 patients (11.3%, 15/133) (12 men; 3 female) in whom outflow block developed after LDLT. Their mean age was 52.3 years ± 15.3 (SD) (range, 4-69 years). Venous stenosis with a pressure gradient ≥5 mmHg (outflow block) was observed in the inferior vena cava in seven patients, hepatic vein in seven patients, and both in one patient. Technical success, change in a pressure gradient and clinical manifestations, and complications were evaluated. Overall survival of 15 patients undergoing outflow block stenting was compared with that of 116 patients without outflow block after LDLT. RESULTS: Stents were placed across the outflow block veins without complications, lowering the pressure gradient ≤ 3 mmHg in all patients (100%, 15/15). Clinical manifestations improved in 11 patients (73.3%, 11/15), and all were discharged from the hospital. However, they did not improve in the other 4 patients (26.7%, 4/15) who died in the hospital 1.0-3.7 months after stenting (mean, 2.0 ± 1.2 months). No significant difference in 5-year survival rates was found between patients with and without outflow block after LDLT (61.1 vs. 72.2%, p = .405). CONCLUSION: Stenting is a feasible, safe, and useful therapeutic option to resolve outflow block following LDLT, providing equal survival to that of patients without outflow block.

Analysis of choriocapillaris flow patterns by continuous laser-targeted angiography in monkeys.

PURPOSE: To investigate choriocapillaris flow patterns and its segmental distribution in monkeys by continuous laser-targeted angiography (LTA). METHODS: A slit lamp was modified to incorporate two kinds of lasers (argon and diode). Carboxyfluorescein (CF) was encapsulated in heat-sensitive liposomes and injected intravenously. Encapsulated CF was released locally by applying a continuous heat beam provided by the diode laser (810 nm). Video angiograms were generated with excitation illumination provided by the argon laser (488 and 514 nm), to observe selective images of the choriocapillaris. RESULTS: Continuous application of the diode laser disclosed three distinct phases (filling, plateau, and draining) of fluorescent images of the choriocapillaris. In the plateau phase, a cluster of lobules fed by a common arteriole was uniformly illuminated. This defined area did not change in size while a continuous diode laser was applied to the same spot. Only in posterior regions did the angiograms demonstrate that during the filling and draining phases each lobule was filled from a central spot and drained along a peripheral ring, showing honeycomb flow patterns. In peripheral regions, large choroidal vessels as well as choriocapillaris were observed. CONCLUSIONS: Continuous LTA demonstrated clusters of lobules fed by a common arteriole, and each cluster was found to be functionally independent. There were regional differences in choriocapillaris flow patterns, which suggests that the choriocapillaris provides a more highly efficient system of outflow in posterior regions than in peripheral regions. This modified LTA method appears to be useful in analyzing choroidal circulation in vivo.